1. Field of the Invention
Aspects of the present invention relate to estimation of a one-way delay time between two hosts, and more particularly, to a method of and an apparatus for estimating a one-way delay time, by which if an m-th one-way delay time obtained by using a round-trip delay time is identical to the time difference of the m-th transmission times measured in respective hosts, a value equal to or less than the obtained m-th one-way delay time is determined as the one-way delay time desired to be estimated, and to a clock synchronization method and apparatus using the same.
2. Description of the Related Art
Clocks of two hosts disposed at a distance may be synchronized with each other or not. As a method of synchronizing the clocks of two hosts that are not synchronized, two hosts may receive identical timing information from a base station of a satellite or a cellular phone, and synchronize the clocks according to the received timing information. However, in this method, in order to receive the timing information, expensive reception equipment such as an antenna is necessary. Accordingly, utilization of the method is low.
As another method of synchronizing the clocks of two hosts that are not synchronized, a one half value of a round-trip delay time measured in one host may be estimated as a one-way delay time of the two hosts, and by using the estimated one-way delay time, two clocks of the hosts may be synchronized. The mid round-trip value method may be usefully employed to synchronize the clocks if two disposed hosts are under an environment where timing information from a satellite or a base station that can be a reference cannot be received. However, the mid round-trip value method has a limitation in that the accuracy of synchronization cannot be guaranteed to be higher than one half the value of the round-trip delay time. Accordingly, an improved method to overcome this limitation is needed.